Early response to venlafaxine antidepressant correlates with lower ACTH levels prior to pharmacological treatment

Cortisol as a Biomarker of Mental Disorder Severity

Cortisol—the most important steroid hormone with a significant effect on body metabolism—strongly affects peripheral tissues and the central nervous system. Fluctuations in cortisol secretion often accompany psychiatric disorders, and normalization of its levels correlates with improvement in the patient’s health. This indicates that cortisol may be useful as a biological marker that can help determine the likelihood of mental illness, its impending onset, and the severity of symptoms, which is especially important in the face of the increasing prevalence of mental disorders, including those associated with social isolation and anxiety during the COVID-19 pandemic. This publication reviews recent reports on cortisol levels in healthy participants and shows the current state of knowledge on changes in the levels of this hormone in people at risk for depression, bipolar disorder, and psychosis. It shows how people with psychiatric disorders react to stressful situations and how the applied therapies affect cortisol secretion. The influence of antidepressants and antipsychotics on cortisol levels in healthy people and those with mental disorders is also described. Finally, it reviews publications on the patterns of cortisol secretion in patients in remission.

Systematic evaluation of the 'efficacy-effectiveness gap' in the treatment of depression with venlafaxine and duloxetine

OBJECTIVE

Evidence of larger drug effects in highly standardized studies (efficacy) compared to clinical routine (effectiveness) is discussed as efficacy-effectiveness gap. This study aimed to quantify effect size differences of RCTs and non-RCTs in the treatment of depression with venlafaxine and duloxetine and to identify effect modifying predictors.

METHODS

A comprehensive systematic review and meta-analysis was conducted, including all prospective trials, which evaluated the treatment effects of duloxetine or venlafaxine in patients with depression. The primary outcome was the pre-post effect size after acute therapy, which were compared between RCTs and non-RCTs. Moreover, an exploratory analysis of predictors in a mixed meta-regression model within an information-theoretic approach was performed.

RESULTS

171 RCTs and 74 non-RCTs were included. The pre-post effect size differed significantly between RCTs and non-RCTs (-3.04 vs. -2.62, Δ = 0.41, p = 0.012, high heterogeneity). Study characteristics were very similar between RCTs and non-RCTs. Most important variables to predict effect sizes were 'depression severity', 'dose' and 'number of participants'.

CONCLUSION

Despite differences in effect sizes between RCTs and non-RCTs, study design is not clearly an important predictor for the effect sizes. Our results question the common assumption that non-RCTs are generally better suited to describe a drug's effectiveness in clinical practice than RCTs. Future studies and their reporting should put more emphasis on the description of external validity, in order to allow better assessments of clinical relevance.

Association of N-cadherin levels and downstream effectors of Rho GTPases with dendritic spine loss induced by chronic stress in rat hippocampal neurons

Chronic stress promotes cognitive impairment and dendritic spine loss in hippocampal neurons. In this animal model of depression, spine loss probably involves a weakening of the interaction between pre- and postsynaptic cell adhesion molecules, such as N-cadherin, followed by disruption of the cytoskeleton. N-cadherin, in concert with catenin, stabilizes the cytoskeleton through Rho-family GTPases. Via their effector LIM kinase (LIMK), RhoA and ras-related C3 botulinum toxin substrate 1 (RAC) GTPases phosphorylate and inhibit cofilin, an actin-depolymerizing molecule, favoring spine growth. Additionally, RhoA, through Rho kinase (ROCK), inactivates myosin phosphatase through phosphorylation of the myosin-binding subunit (MYPT1), producing actomyosin contraction and probable spine loss. Some micro-RNAs negatively control the translation of specific mRNAs involved in Rho GTPase signaling. For example, miR-138 indirectly activates RhoA, and miR-134 reduces LIMK1 levels, resulting in spine shrinkage; in contrast, miR-132 activates RAC1, promoting spine formation. We evaluated whether N-cadherin/β-catenin and Rho signaling is sensitive to chronic restraint stress. Stressed rats exhibit anhedonia, impaired associative learning, and immobility in the forced swim test and reduction in N-cadherin levels but not β-catenin in the hippocampus. We observed a reduction in spine number in the apical dendrites of CA1 pyramidal neurons, with no effect on the levels of miR-132 or miR-134. Although the stress did not modify the RAC-LIMK-cofilin signaling pathway, we observed increased phospho-MYPT1 levels, probably mediated by RhoA-ROCK activation. Furthermore, chronic stress raises the levels of miR-138 in accordance with the observed activation of the RhoA-ROCK pathway. Our findings suggest that a dysregulation of RhoA-ROCK activity by chronic stress could potentially underlie spine loss in hippocampal neurons.

Hypothalamic-pituitary-adrenocortical axis: neuropsychiatric aspects

Evidence of aberrant hypothalamic-pituitary-adrenocortical (HPA) activity in many psychiatric disorders, although not universal, has sparked long-standing interest in HPA hormones as biomarkers of disease or treatment response. HPA activity may be chronically elevated in melancholic depression, panic disorder, obsessive-compulsive disorder, and schizophrenia. The HPA axis may be more reactive to stress in social anxiety disorder and autism spectrum disorders. In contrast, HPA activity is more likely to be low in PTSD and atypical depression. Antidepressants are widely considered to inhibit HPA activity, although inhibition is not unanimously reported in the literature. There is evidence, also uneven, that the mood stabilizers lithium and carbamazepine have the potential to augment HPA measures, while benzodiazepines, atypical antipsychotics, and to some extent, typical antipsychotics have the potential to inhibit HPA activity. Currently, the most reliable use of HPA measures in most disorders is to predict the likelihood of relapse, although changes in HPA activity have also been proposed to play a role in the clinical benefits of psychiatric treatments. Greater attention to patient heterogeneity and more consistent approaches to assessing treatment effects on HPA function may solidify the value of HPA measures in predicting treatment response or developing novel strategies to manage psychiatric disease.

Relationship of cortisol levels and genetic polymorphisms to antidepressant response to placebo and fluoxetine in patients with major depressive disorder: a prospective study

BACKGROUND

Increased cortisol levels and genetic polymorphisms have been related to both major depressive disorder and antidepressant treatment outcome. The aim of this study is to evaluate the relationship between circadian salivary cortisol levels, cortisol suppression by dexamethasone and genetic polymorphisms in some HPA axis-related genes to the response to placebo and fluoxetine in depressed patients.

METHODS

The diagnosis and severity of depression were performed using the Mini International Neuropsychiatric Interview (M.I.N.I.) and Hamilton depression scale (HAM-D17), respectively. Euthyroid patients were treated with placebo (one week) followed by fluoxetine (20 mg) (two months). Severity of depression was re-evaluated after placebo, three weeks and two months of fluoxetine treatments. Placebo response was defined as HAM-D17 score reductions of at least 25% and to < 15. Early response and response were reductions of at least 50% after three weeks and two months, and remission with ≤ 7 after two months. Plasma TSH, free-T4, circadian salivary cortisol levels and cortisol suppression by dexamethasone were evaluated. Seven genetic polymorphisms located in the Corticotrophin-releasing-hormone-receptor-1 (rs242939, rs242941, rs1876828), Corticotrophin-releasing-hormone-receptor-2 (rs2270007), Glucocorticoid-receptor (rs41423247), FK506-binding-protein-5 (rs1360780), and Arginine-vasopressin (rs3729965) genes were determined. Association analyses between response to placebo/fluoxetine and polymorphism were performed by chi-square or Fisher exact test. Cortisol levels were compared by t-test, ANOVA and the general linear model for repeated measures.

RESULTS

208 depressed patients were recruited, 187 of whom were euthyroid. Placebo responders, fluoxetine responders and remitters exhibited significantly lower circadian cortisol levels than those who did not respond (p-values of 0.014, 0.008 and 0.021 respectively). Patients who abandoned treatment before the third week also exhibited a trend to low cortisol levels (p = 0.057). The polymorphisms rs242939 (CRHR1) and rs2270007 (CRHR2) were not in Hardy-Weinberg equilibrium. Only the rs242939 polymorphism (CRHR1) exhibited association with early response (three weeks) to fluoxetine (p-value = 0.043). No other association between outcomes and polymorphisms was observed.

CONCLUSIONS

These results support the clinical relevance of low salivary cortisol levels as a predictor of antidepressant response, either to placebo or to fluoxetine. Only one polymorphism in the CRHR1 gene was associated with the early response. Other factors may be involved in antidepressant response, although further studies are needed to identify them.

Sex, stress, and mood disorders: at the intersection of adrenal and gonadal hormones

The risk for neuropsychiatric illnesses has a strong sex bias, and for major depressive disorder (MDD), females show a more than 2-fold greater risk compared to males. Such mood disorders are commonly associated with a dysregulation of the hypothalamo-pituitary-adrenal (HPA) axis. Thus, sex differences in the incidence of MDD may be related with the levels of gonadal steroid hormone in adulthood or during early development as well as with the sex differences in HPA axis function. In rodents, organizational and activational effects of gonadal steroid hormones have been described for the regulation of HPA axis function and, if consistent with humans, this may underlie the increased risk of mood disorders in women. Other developmental factors, such as prenatal stress and prenatal overexposure to glucocorticoids can also impact behaviors and neuroendocrine responses to stress in adulthood and these effects are also reported to occur with sex differences. Similarly, in humans, the clinical benefits of antidepressants are associated with the normalization of the dysregulated HPA axis, and genetic polymorphisms have been found in some genes involved in controlling the stress response. This review examines some potential factors contributing to the sex difference in the risk of affective disorders with a focus on adrenal and gonadal hormones as potential modulators. Genetic and environmental factors that contribute to individual risk for affective disorders are also described. Ultimately, future treatment strategies for depression should consider all of these biological elements in their design.

Serum brain-derived neurotrophic factor and glucocorticoid receptor levels in lymphocytes as markers of antidepressant response in major depressive patients: a pilot study

Depressive patients often have altered cortisol secretion, an effect that likely derives from impaired activity of the glucocorticoid receptor (GR), the main regulator of the hypothalamus-pituitary-adrenal (HPA) axis. Glucocorticoids reduce the levels of brain-derived neurotrophic factor (BDNF), a downstream target of antidepressants. Antidepressants promote the transcriptional activity of cyclic adenosine monophosphate (cAMP) response element binding protein (CREB), a regulator of BDNF expression. To identify potential biomarkers for the onset of antidepressant action in depressive patients, GR and phospho-CREB (pCREB) levels in lymphocytes and serum BDNF levels were repeatedly measured during the course of antidepressant treatment. Thirty-four depressed outpatients (10 male and 24 female) were treated with venlafaxine (75mg/day), and individuals exhibiting a 50% reduction in their baseline 17-Item Hamilton Depression Rating Scale score by the 6th week of treatment were considered responders. Responders showed an early improvement in parallel with a rise in BDNF levels during the first two weeks of treatment. Non-responders showed increased GR levels by the third week and reduced serum BDNF by the sixth week of treatment. In contrast, venlafaxine did not affect levels of pCREB. We conclude that levels of BDNF in serum and GR levels in lymphocytes may represent biomarkers that could be used to predict responses to venlafaxine treatment.

A single DEX/CRH test in male drug-free depressed patients is associated with the clinical response to treatment with fluoxetine

OBJECTIVES

The DEX/CRH test has been proposed to be suitable as a biomarker for the prediction of treatment response in depression.

METHODS

We performed the DEX/CRH test in 10 severely depressed male patients with melancholic features before initiation of antidepressant treatment with 20 mg fluoxetine.

RESULTS

We found a low cortisol response (as measured by cortisol AUC) to a single DEX/CRH test to be associated with clinical response to treatment.

CONCLUSIONS

A strength of this study lies in the inclusion of patients after a drug wash-out phase. Despite a certain inconsistency described in the literature, several studies support the notion that it might be of importance to measure baseline HPA system activity before choice of treatment. Further systematic studies are warranted.

Antidepressant treatment with mirtazapine, but not venlafaxine, lowers cortisol concentrations in saliva: a randomised open trial

Lowering the concentrations of free cortisol in depressed patients may be an important prerequisite to prevent glucocorticoid-related sequelae of depression. We tested the hypothesis that the hypothalamus-pituitary-adrenal (HPA) system-dampening effects of venlafaxine and mirtazapine differ. We compared the course of morning (08.00h) and afternoon saliva cortisol (16.00h) in 42 mirtazapine- and 45 venlafaxine-treated depressed patients during a 1-week wash-out and a 4-week treatment period in a randomised open trial. Mirtazapine lowered afternoon cortisol from week 1 to 4. In contrast, during the course of the entire treatment period, venlafaxine did not attenuate saliva cortisol concentrations. Treatment effects of mirtazapine on cortisol concentrations did not differ in remitters and non-remitters to treatment. High baseline cortisol concentrations, on the other hand, were related to an unfavourable course during venlafaxine treatment and patients remitting during venlafaxine treatment had significantly lower afternoon cortisol concentrations in saliva, when compared to non-remitting patients. Thus, mirtazapine and venlafaxine show different effects on HPA system activity as measured by saliva cortisol. This may be of relevance with regard to physical sequelae of depression.